我从 osmdroid 获得了这些代码或补丁，我决定寻求你们的帮助，因为我没有足够的知识来组合这些代码来解决我的问题，离线地图上的滚动限制. 我在网上搜索，并修改了教程。老实说，我试图修改这些代码，但我没有发现任何进展。基本上我有一张来自 mapnik 的离线地图，还有一些叠加层。我不知道在哪里正确放置这些代码集。你的想法和修改将是一个很大的帮助，也帮助我继续我的项目，我想你的答案肯定会帮助其他人在未来遇到同样的问题。我知道这太过分了。谢谢先生们的宝贵时间，上帝保佑。
public void onCreate(Bundle savedInstanceState) {
...
...
m_mapView = (MapView) findViewById(R.id.mapview);
m_mapView.setTileSource(TileSourceFactory.MAPNIK);
}
第一个：边界框
BoundingBoxE6 bbox = new BoundingBoxE6(9.37398, 123.33761, 9.23948, 123.25035);
this.setScrollableAreaLimit(bbox);
第二：LimitScrollToGeographicArea.patch
Index: MapView.java
===================================================================
--- MapView.java (revision 944)
+++ MapView.java (working copy)
@@ -103,6 +103,8 @@
protected MapListener mListener;
+ protected Rect mScrollableAreaLimit;
+
// for speed (avoiding allocations)
private final Matrix mMatrix = new Matrix();
private final MapTileProviderBase mTileProvider;
@@ -505,6 +507,36 @@
mMapOverlay.setUseDataConnection(aMode);
}
+ /**
+ * Set the map to limit it's scrollable view to the specified BoundingBoxE6. Note that, like
+ * North/South bounds limiting, this allows an overscroll of half the screen size. This means
+ * each border can be scrolled to the center of the screen.
+ *
+ * @param boundingBox
+ * A lat/long bounding box to limit scrolling to, or null to remove any scrolling
+ * limitations
+ */
+ public void setScrollableAreaLimit(BoundingBoxE6 boundingBox) {
+ final int worldSize_2 = TileSystem.MapSize(MapViewConstants.MAXIMUM_ZOOMLEVEL) / 2;
+
+ // Clear scrollable area limit if null passed.
+ if (boundingBox == null) {
+ mScrollableAreaLimit = null;
+ return;
+ }
+
+ // Get NW/upper-left
+ final Point upperLeft = TileSystem.LatLongToPixelXY(boundingBox.getLatNorthE6() / 1E6,
+ boundingBox.getLonWestE6() / 1E6, MapViewConstants.MAXIMUM_ZOOMLEVEL, null);
+ upperLeft.offset(-worldSize_2, -worldSize_2);
+
+ // Get SE/lower-right
+ final Point lowerRight = TileSystem.LatLongToPixelXY(boundingBox.getLatSouthE6() / 1E6,
+ boundingBox.getLonEastE6() / 1E6, MapViewConstants.MAXIMUM_ZOOMLEVEL, null);
+ lowerRight.offset(-worldSize_2, -worldSize_2);
+ mScrollableAreaLimit = new Rect(upperLeft.x, upperLeft.y, lowerRight.x, lowerRight.y);
+ }
+
// ===========================================================
// Methods from SuperClass/Interfaces
// ===========================================================
@@ -772,10 +804,26 @@
//I am confused with these codes below, where should I declare it? Int x, y in the onCreate method?
x += (worldSize_2 * 2);
while (x > worldSize_2)
x -= (worldSize_2 * 2);
- while (y < -worldSize_2)
- y += (worldSize_2 * 2);
- while (y > worldSize_2)
- y -= (worldSize_2 * 2);
+ if (y < -worldSize_2)
+ y = -worldSize_2;
+ if (y > worldSize_2)
+ y = worldSize_2;
+
+ if (mScrollableAreaLimit != null) {
+ final int zoomDiff = MapViewConstants.MAXIMUM_ZOOMLEVEL - getZoomLevel();
+ final int minX = mScrollableAreaLimit.left >> zoomDiff;
+ final int minY = mScrollableAreaLimit.top >> zoomDiff;
+ final int maxX = mScrollableAreaLimit.right >> zoomDiff;
+ final int maxY = mScrollableAreaLimit.bottom >> zoomDiff;
+ if (x < minX)
+ x = minX;
+ else if (x > maxX)
+ x = maxX;
+ if (y < minY)
+ y = minY;
+ else if (y > maxY)
+ y = maxY;
+ }
super.scrollTo(x, y);
// do callback on listener
另一个：
scrollToMethod
public void scrollTo(int x, int y) {
int curZoomLevel = mZoomLevel;
final int worldSize_2 = TileSystem.MapSize(curZoomLevel) / 2;
Log.v("HELP", "Scrolling to X=" + x + " Y=" + y + " ZL=" + curZoomLevel + " - WW="+worldSize_2);
while (x < -worldSize_2)
x += (worldSize_2 * 2);
while (x > worldSize_2)
x -= (worldSize_2 * 2);
if (y < -worldSize_2)
y = -worldSize_2;
if (y > worldSize_2)
y = worldSize_2;
if (mScrollableAreaLimit != null) {
int targetZoomLevel = getZoomLevel();
final int zoomDiff = MapViewConstants.MAXIMUM_ZOOMLEVEL - targetZoomLevel;
//final int zoomDiff = MapViewConstants.MAXIMUM_ZOOMLEVEL - mZoomLevel;
final int minX = mScrollableAreaLimit.left >> zoomDiff;
final int minY = mScrollableAreaLimit.top >> zoomDiff;
final int maxX = mScrollableAreaLimit.right >> zoomDiff;
final int maxY = mScrollableAreaLimit.bottom >> zoomDiff;
Log.v("HELP", "Limit: minX=" + minX + " maxX=" + maxX + " minY=" + minY + " maxY=" + maxY + " ZL=" + curZoomLevel + " ZLTarget="+ targetZoomLevel + " ZD="+zoomDiff);
if (x < minX) {
Log.v("HELP", "!!! X=" + x + " minX=" + minX + " CORRECTION:" + (minX-x));
x = minX;
} else if (x > maxX) {
Log.v("HELP", "!!! X=" + x + " maxX=" + maxX + " CORRECTION:" + (maxX-x));
x = maxX;
}
if (y < minY) {
Log.v("HELP", "!!! Y=" + y + " minY=" + minY + " CORRECTION:" + (minY-y));
y = minY;
} else if (y > maxY) {
Log.v("HELP", "!!! Y=" + y + " maxY=" + maxY + " CORRECTION:" + (maxY-y));
y = maxY;
}
}
super.scrollTo(x, y);
// do callback on listener
if (mListener != null) {
final ScrollEvent event = new ScrollEvent(this, x, y);
mListener.onScroll(event);
}
}